The theory of relativity has been hailed as one of the two most important scientific discoveries in the 20th century. This book presents a comprehensive introduction and analysis of the special theory of relativity and its logical and experimental foundations. It explains in detail the basic principles of the relativity theory, introduces all the important experiments and examines the logic in the reasoning of relativistic results and conclusions. The two fundamental postulates, the principle of relativity and the constancy of the speed of light, are extensively discussed in relation to historical and modern experimental findings. The interpretations of all important experimental results in the history of special relativity and the derivations of key theoretical results in special relativity are scrutinized for their logical consistency, uniqueness to special relativity, and simplicity in explanation compared with competing theories. The ten chapters of this book cover 1) the two postulates, their experimental evidence and logical foundation; 2) the Michelson-Morley experiment and all other important experiments on the speed of light and the medium of light including stellar aberration, the Fizeau experiment, Trouton experiment, Trouton-Noble experiment, Sagnac experiment, Kennedy-Thorndike experiment, Ives-Stilwell experiment, and many modern experiments; 3) the derivation of the Lorentz transformation; 4) the variables in the Lorentz transformation and the principle of relativity; 5) time dilation, its experimental evidence and the twin paradox; 6) length contraction and length paradoxes; 7) motion mass and its derivation, relativistic momentum and experimental evidence; 8) mass-energy relation, its derivation and experimental evidence; 9) time and simultaneity; 10) test theories and experimental verification of special relativity. This book is suitable for both academics and students in science and philosophy and other readers who are interested in physics and its associated philosophical issues; space-time theories; the logical foundation of scientific discoveries; the history of science; the methodology of science, especially researchers and students in physics and the philosophy of science.